Conventionally, there are many techniques relating to game systems for providing battle games using cards possessed by users. For example, Patent Document JP2008-220984 A describes a game device for playing a battle using a deck that is composed of a predetermined number of cards. In particular, Patent Document JP2008-220984 A discloses a technique relating to a game device that includes control means for outputting, as advice, a deck evaluation message evaluating a deck selected by a game player.